Last Sync: 2022-08-04 14:00:04

Programming_Languages/NodeJS/REST_APIs/1_GET.md

@@ -66,6 +66,17 @@ app.get("/api/courses/:id", (req, res) => {
 
 We use the `:` symbol in the URI to indicate that we looking to parse for a specific value in the data. Now if we call `/api/courses/2`, we will get the second item in the array.
 
+The block above is the most basic format but we would want to add some kind of error handling, for example:
+
+```js
+app.get("/api/courses/:id", (req, res) => {
+  const course = courses.find((c) => c.id === parseInt(req.params.id));
+  if (!course) res.status(404).send("A course with the given ID was not found");
+  res.send(course);
+});
+```
+
+
 ## Queries
 
 Whereas parameters return specific data points, queries don't get data they aggregate or present the data that is returned in a certain way, such as for instance applying a search function. We indicate queries with a `?` in our URI.

Programming_Languages/NodeJS/REST_APIs/2_PUT.md

@@ -0,0 +1,58 @@
+---
+tags:
+  - Programming_Languages
+  - backend
+  - node-js
+  - express
+  - REST
+  - apis
+---
+
+# Creating a REST API with Node and Express: POST requests
+
+To demonstrate the handling of POST requests, we will create a handler that add a new element to the array of courses.
+
+```js
+app.post('/api/courses', (req, res) => {
+	const course = {
+		id: courses.length + 1,
+		name: req.body.name
+	}
+	courses.push(course);
+	res.send(course)
+
+})
+```
+
+Here we use the body that is sent from the client and isolate the field `name`. This presupposes that the client is sending us data with the following shape as the body:
+
+```json
+{
+	"name": "Biology and Life Sciences"
+}	
+```
+
+To execute the PUT request from the frontend:
+
+```js
+const addCourse = async (newCourse) => {
+  try {
+    const resp = await axios.post("http://localhost:3000/api/courses", {
+      name: newCourse,
+    });
+    console.log(resp.data);
+  } catch (err) {
+    console.error(err);
+  }
+};
+
+addCourse("Biology and Life Sciences");
+```
+
+Which returns: 
+
+```js
+{ id: 4, name: 'Biology and Life Sciences' }
+```
+
+The `id` is added by the server, not the client. Having created the new value we add it to our `courses` array. (In reality we would be creating a new entry in a database.) Then we follow the convention of returning the new value back to the client.